An engineer has a full$-$time position as a structural engineer at an Architecture and Engineering firm. During the weekends, the engineer works on privately obtained consulting jobs. Occasionally, for the consulting job, the engineers uses a Structural Analysis and Design software which is licensed to his employer, to which has access using a remote VPN connection from home. This action is most probably unethical because:

The access gives the engineer an unfair economic advantage.

The engineer's employment contract prohibits misuse and misappropriation of the software license.

The use of the software on private computers can make the software vulnerable to computer viruses and render it unoperational.

The company has not given the engineer permission to use the software for outside contracts.