Answer:
0π
Step-by-step explanation:
After you add 5 and divide by 7, you find you're looking for solutions to ...
cos(θ) = 1
Your knowledge of the cosine function tells you the solution is ...
θ = 0 . . . . . matches the last choice (only)
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Any multiple of 2π is a solution, but the only one in the allowed domain is 0π.