When You Do External Calls to Other Smart Contracts

Multiple Choice

When you do external calls to other smart contracts:

A) you should follow the checks-effects-interactions pattern and avoid state changes after the call.
B) you should follow the effects-checks-interactions pattern and avoid state changes before the call.
C) you should follow the checks-effects-interactions pattern, which is only necessary when you do calls to contracts where a direct contract call is not possible.