The wires `A` and `B` shown in Fig. are made of the same material and have radii `r_(A)` and `r_(B)`, respectively. The block between them has a mass `m`. When the force `F` is `mg//3`, one of the wires breaks. Then
A. A will break before B is `r_(A)=r_(B)`
B. A will break before B is `r_(A)lt2r_(B)`
C. Either A or B may break if `r_(A)=2r_(B)`
D. The length of A and B must be known to predict which wire will break.