The straight line is shown below with the intercepts.

M(2cosθ7,2sinθ7)≡(h,k)
∴cosθ=2h7sinθ=2k7
∵θ∈(0,2π)
⇒4h249+4k249=1∴x and y are positive
∴ Locus =x21+y21=494
Now (α,373) lies on curve
⇒α21+1479=494
α21=491
∴α=±7
∴α=7
Hence this is the required option.