C. Cannot be determined
D. Yes, only when the 10V source is removed
I had been asked this question in examination.
Origin of the question is Kirchhoff’s Laws and Network Solutions topic in chapter Network Theorems of Basic Electrical Engineering
Easy explanation: The 15A current source has a lower resistance path associated with it and hence it keeps moving in that particular loop. It does not leave that loop and enter the circuit, hence the circuit is not affected by it.