Step 1: Understand the stem meaning.
The phrase “Despite his best efforts to conceal his anger” sets up a contrast—he tried to hide anger but was unsuccessful.
Step 2: Match with correct logical continuation.
Only option (d) clearly indicates failure of concealment—others either suggest unrelated feelings (happy), partial meaning (agony), or success in hiding emotions (option 3, which contradicts “despite” here).
\[
\boxed{\text{(d) people came to know that he was annoyed}}
\]