Acceleration of pulleys and blocks are as shown in the figure. All pulleys & strings are massless & frictionless magnitude of `a_(A)` and `a_(B)` are :
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A. `a_(A) = 0, a_(B) = 7`
B. `a_(A) = 0, a_(B) = 5`
C. `a_(A) = 0, a_(B) = 12`
D. `a_(A) = 5, a_(B) = 7`