Every FD is a MVD.
i.e suppose $x\rightarrow y$ $\Rightarrow$ $x\rightarrow \rightarrow y$
If y can be determined by x on y's single value then we can easily say x multi-determines y. as single value $\subseteq$ multiple value.
Now,
1. can't even possible.
2. A -> BC which implies A -> -> BC. (true)
3. using given data we can't prove the then part.
4. given FDs are A->B & A->C, so using this we can say A->->C.(true)
here 2 implications are valid. i.e option C