The SAS program provided includes a PROC FORMAT step that defines a numeric format called Syn and applies this format to the variable answer in the PROC PRINT step. The format maps the value '0' to 'No', '1' to 'Yes', and all other values to 'Unknown'.
However, there is a syntax error in the PROC FORMAT step: it uses a dollar sign before Syn, which is used to indicate character formats, but the format is defined for numeric values (0 and 1). Therefore, when applying this format to the answer variable in PROC PRINT, it should not have a dollar sign, it should be format answer Syn.; instead of format answer $yn.;.
The correct output based on the given code, assuming the error with the dollar sign is corrected, would be as follows:
* For numeric values 0 and 1, 'No' and 'Yes' would be displayed, respectively.
* For any other numeric value, 'Unknown' would be displayed.
* For character values, the format would not apply and the actual values would be displayed.
Given that the values in the 'answer' column are numeric, the program will format them according to the defined Syn format. Thus, the report corresponding to Option D, which shows numeric values unformatted, would be the one created. This indicates that the format was not applied because of the syntax error with the dollar sign.
References:
* SAS 9.4 documentation for the FORMAT procedure and statement: SAS Help Center: PROC FORMAT

The type and length of SnackType are character and 7, which makes option B correct. In the provided program, SnackType is assigned a value of "Chips" which is a character string. The length statement is used to explicitly declare SnackType as a character variable with a length of 7 before it is used, which will take precedence over any later assignments or implications about the variable's type or length.
References:
* SAS documentation on variable length.

The program fails because option C is correct: you must include the dataset height2 in the DATA statement.
The DATA step is trying to write to a dataset named height2, which has not been defined in the DATA statement. The correct syntax to create two datasets in one DATA step is to list them both in the DATA statement like so:
data height1 height2;
The use of numbers in dataset names is not a problem in SAS, nor is outputting to different data sets within a single DATA step. Additionally, using two different DATA statements for HEIGHT1 and HEIGHT2 is not required and is not the cause of the failure.
References:
* SAS documentation on the DATA statement and creating multiple data sets.