Answer
(a) Small sphere -Positive charge
(b) Inner surface of hollow sphere - Negative charge
(c) Outer surface of hollow sphere - Positive charge.
Work Step by Step
The small sphere will be positively charged due to charge transferred by wire. This positive charge will induce a negative charge on the inner surface of hollow sphere and as hollow sphere is neutral so, there will be a positive charge on outer surface of hollow sphere.
Hence,
(a) Small sphere -Positive charge
(b) Inner surface of hollow sphere - Negative charge
(c) Outer surface of hollow sphere - Positive charge.