Quiz: Subordinates Technique

Subordinates problem: Count employees under each manager in a company tree. Node $v$ has $3$ direct reports with subordinate counts $5$, $2$, and $0$. What's $v$'s subordinate count?

1. A.$10$ (sum of children's counts plus direct reports)
2. B.$3$ (only direct reports)
3. C.$7$ (sum of children's counts)
4. D.$8$ (sum plus $1$)