In the Case of an Unanticipated Increase in Inflation

In the case of an unanticipated increase in inflation:

A) creditors with an unindexed contract are hurt because they get less than they expected in real terms.
B) creditors with an indexed contract gain because they get more than they contracted for in nominal terms.
C) debtors with an unindexed contract do not gain because they pay exactly what they contracted for in nominal terms.
D) debtors with an indexed contract are hurt because they pay more than they contracted for in nominal terms.