Answer: Option A
$$\eqalign{
& {\text{We have,}} \cr
& 1 \times 2 \times 3 \times 4 = 24 \cr
& {\text{And }}24 + 1 = 25\left[ {25 = {5^2}} \right] \cr
& 2 \times 3 \times 4 \times 5 = 120{\text{ }} \cr
& {\text{And 1}}20 + 1 = 121\left[ {121 = {{11}^2}} \right] \cr
& 3 \times 4 \times 5 \times 6 = 360{\text{ }} \cr
& {\text{And }}360 + 1 = 361\left[ {361 = {{19}^2}} \right] \cr
& 4 \times 5 \times 6 \times 7 = 840{\text{ }} \cr
& {\text{And }}840 + 1 = 841\left[ {841 = {{29}^2}} \right] \cr
& \therefore p = 1 \cr} $$