(A)tangential acceleration is2m/s2
centripetal acceleration is v2/R=4/2=2
Now→a.→v=avcosθ=atangentialv=4
A->3
(B)ω is perpendicular to the plane of motion therefore, →a×→ω=aω=2√2×v/R=2√2
B->1
(C) →v.→ω=0 because v is perpendicular to ω
C->4
(D) →v×→a=vasinθ=vacentripetal=2×2=4
D->3