The correct option is
B Statement II alone but not statement I alone is sufficient to answer the problem
From statement II :
One piece is 20 cm long, so other two pieces together will be 480cm long.
Suppose length of first piece is x and of second piece is y.
∴ x+y=480 .............. (1)
And x+90=y
Substitute the value of y in (1) and we get,
x+x+90=480 ⟹ 2x=390
∴ x=195
Substituting x in x+90=y we get
y=285.
So, the longest piece is of 285cm.
Thus, from statement II only we can get the longest piece.
But from only I we can't get the required result.
Hence, option B is correct.