Question

Given a tree ( T ) with ( n ) nodes, how many subtrees ( T' ) of ( T ) have at most ( k ) edges connected to ( (T - T') )?
a) ( nᵏ )
b) ( 2ⁿ )
c) ( nᵏ⁺¹ )
d) ( 2ᵏ⁺¹ )