This kind of an attack involves altering the raw data just before it is processed by a computer and then changing it back after the processing is completed. This kind of attack was used in the past to make what is stated in the question, steal small quantities of money and transfer them to the attackers account. See "Data deddling crimes" on the Web.
The most correct answer is 'Salami', but since that is not an option the most correct answer is data diddling.
"A salami attack is committing several small crimes with the hope that the overall larger crime will go unnoticed. ....An example would be if an employee altered a banking software program to subtract 5 cents from each of the bank's customers' accounts once a month and moved this amount to the employee's bank account. If this happened to all of the bank's 50,000 customer accounts, the intruder could make up to $ 30,000 a year.
Data diddling refers to the alteration of existing data. Many times this modification happens before it is entered into an application or as soon as it completes processing and is outputted from an application.
There was an incident in 1997, in Maryland, where a Taco Bell employee was sentenced to ten years in jail because he reprogrammed the drive-up window cash register to ring up ever 42.99 order as one penny. He collected the full amount from the customer, put the penny in the till, and pocketed the other $2.98. He made $3600 before his arrest."
Pg. 602-603 Shon Harris: All-In-One CISSP Certification Exam Guide

It is not a property of Bell LaPadula model.
The other answers are incorrect because:
A subject is not allowed to read up is a property of the 'simple security rule' of Bell
LaPadula model.
The *- property restriction can be escaped by temporarily downgrading a high level subject can be escaped by temporarily downgrading a high level subject or by identifying a set of trusted objects which are permitted to violate the *-property as long as it is not in the middle of an operation.
It is restricted to confidentiality as it is a state machine model that enforces the confidentiality aspects of access control.
Reference: Shon Harris AIO v3 , Chapter-5 : Security Models and Architecture , Page:279-
282

Discretionary control is the most common type of access control mechanism implemented in computer systems today. The basis of this kind of security is that an individual user, or program operating on the user's behalf, is allowed to specify explicitly the types of access other users (or programs executing on their behalf) may have to information under the user's control. Discretionary security differs from mandatory security in that it implements the access control decisions of the user. Mandatory controls are driven by the results of a comparison between the user's trust level or clearance and the sensitivity designation of the information.