If $M_{1}$ number of people can do $W_{1}$ work, in $D_{1}$ days, working $T_{1}$ hours each day and the $M_{2}$ number of people can do $W_{2}$ work, in $D_{2}$ days, working $T_{2}$ hours each day, then the relation between them will be
$$ \dfrac{M_{1} \times D_{1} \times T_{1}}{W_{1}} = \dfrac{M_{2} \times D_{2} \times T_{2}}{W_{2}} $$
Now, $52 M \times 10 D = 40 M \times xD$
$\implies x = 13$ days.
The number of days, more than the original estimate, that will be required to complete the strip $ = 13 – 10 = 3$ days.
So, the correct answer is $(A).$