Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is ___________________?

Which of the following is true?

A. Error of casting affects personal accounts
B. Omission of a transaction from a subsidiary record affects only one account
C. Error of carry forward affects two accounts
D. Error of principle involves an incorrect allocation of expenditure or receipt between capital and revenue

Errors of casting can appear in any account and not personal accounts alone. Hence statements A. is false. Omission of a transaction from subsidiary affects two accounts are subsidiary books are books of original entry hence posting in two accounts is omitted.
Statement B. is false. Error of carry forward affects only one account i.e., the account in whose an error has been made.
Statement C. is false. Errors of principle involve incorrect allocation of an item between capital and revenue. Hence statement D. is true.