Concept:
Gwalior Gharana is one of the oldest and most important Khayal gharanas of Hindustani music.
Several great musicians are associated with this gharana.
Step 1: Check Hassu Khan.
Hassu Khan is associated with Gwalior Gharana.
So, A is correct.
Step 2: Check Rahamat Khan.
Rahamat Khan is also associated with the Gwalior tradition.
So, C is correct.
Step 3: Check Krishna Rao Shankar Pandit.
Krishna Rao Shankar Pandit is an important representative of Gwalior Gharana.
So, E is correct.
Step 4: Check other names.
Bhimsen Joshi is associated with Kirana Gharana.
Gulam Mustafa Khan is associated with Rampur-Sahaswan tradition.
So, B and D are not correct for Gwalior Gharana.
Step 5: Final conclusion.
The correct representatives are:
\[
A,\ C,\ E
\]
Hence:
\[
\boxed{\text{(C) A, C and E only}}
\]