The correct option is C f1(x)=x(7x−17x+1)
If a graph of a function has to be symmetrical about y−axis, then it has to be an even function.
Now,
f1(−x)=f1(x)⇒f1(x) is even function
f2(−x)=f2(x)⇒f2(x) is even function
f3(−x)=−f3(x)⇒f3(x) is odd function
f4(−x)=−x3+3⇒f3(x) is neither even nor odd function.