What is Which of the following is a Lyase? and explain in detail?
Lyases: Enzymes specialised in the addition or removal of water, ammonia, CO2 etc.
Some examples of Lyases are:

HMG CoA Lyase
Argininosuccinate Lyase
ATP Citrate Lyase
Aldolase
Fumarase.

Reference- Satyanarayana Pg-87