Based on the methods used to separate the substance into its parts, is Substance U a compound?

Question

a
Yes, it is a compound, because chemical methods were used to separate its parts.
b
No, it is a mixture, because chemical methods were used to separate its parts.
c
Yes, it is a compound, because physical methods were used to separate its parts.
d
No, it is a mixture, because physical methods were used to separate its parts.

Answer 1

a
Yes, it is a compound, because chemical methods were used to separate its parts.