Can power of attorney holder gift property to his son or grandson?

In 1985, Mr. A became the owner of a property through registered sale deed. In 1988, Mr. A executed a registered general power of attorney in favour of Mr. B, in which it was mentioned that Mr. B can sell or transfer the property to anyone. Thereafter in 2013, Mr. B transferred the property to his grandson Mr. C through registered gift deed. Q1. Can Mr. B gift the said property to his grandson Mr. C ? Q2. Is there any relevance of death of Mr. A ? Q3. Is gift deed legally valid if Mr. A had died before the execution of gift deed ? Q4. Who is the owner of the property now ? Q5. Can Mr. C further sell the property to anyone ?