Explanation
Humidity is the amount of water vapor in the air. High humidity can cause corrosion, condensation, and short circuits in electronic devices. Low humidity can cause static electricity and damage sensitive components. The optimal humidity range for a data center is between 40% and 60%. Based on the report, the humidity level in the server room is 70%, which is too high and can affect the performance and reliability of the network equipment. Therefore, the best recommendation to the client is to install a humidity sensor and a dehumidifier to control the humidity level in the server room.
References: Network+ Study Guide Objective 5.1: Summarize the importance of physical security controls.

Split tunnel VPN configuration is where only traffic for the private network is routed via the VPN gateway.

A door lock would be the best security device to use to provide mechanical access control to the MDF/IDF. A door lock is a device that prevents unauthorized access to a physical area by requiring a key, a code, a card, a biometric scan, or a combination of these factors to open it. A door lock can provide mechanical access control to the MDF/IDF, which are rooms that house network equipment such as switches, routers, servers, or patch panels. A door lock can prevent unauthorized persons from tampering with or stealing the network equipment or data. References:
https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Data_Center/DC_Infra2_5/DCInfra_6.html