The correct option is C 63
The aleurone layer describes one of the two major cell types of the endosperm. The aleurone layer is the outermost layer of the endosperm, followed by the inner starchy endosperm. The ploidy of endosperm in angiosperm is 3n (central cell fused with one male gamete i.e. 2n+n). The root tip cell is diploid (2n) = 42, so n will be 21. Thus the endosperm will be 3n=21*3=63.
So, the correct option is option C.