Help me... 15 points

How do you answer this question? (step by step)

If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system? a. there are infinitely many solutions. b. there is no solution. c. there is exactly one solution. d. the lines in a system cannot be parallel.

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap