Correct Option: A

According to question,
Roshan is taller than Hardik who is shorter than Sushil.
R > Hardik But Hardik < S.
Niza is taller than Harry but shorter than Hardik.
N > Harry But N < Hardik
Sushil is shorter than Roshan.
S < R
Descending order of the heights is as
Roshan > Sushil > Hardik > Niza > Harry.
Therefore, the tallest person is Roshan.