Do cost-complexity pruned trees perform better relative to unpruned trees?

I came across an adapted question from the famous ISLR book and realise I am unsure of the answer. Does anyone know? Interested in the intuition here!

Cost-complexity pruned trees with $\alpha=1$ relative to unpruned trees (select one):

a. Will have better performance due to increased flexibility when its increase in bias is less than its decrease in variance.

b. item Will have better performance due to increased flexibility when its increase in variance is less than its decrease in bias.

c. item Will have better performance due to decreased flexibility when its increase in bias is less than its decrease in variance.

d. item Will have better performance due to decreased flexibility when its increase in variance is less than its decrease in bias.