Answer:
b. Dehydration synthesis gives out water as a product. 
a. Hydrolysis reaction uses water as a reactant. 
Step-by-step explanation:
b. Dehydration synthesis can be defined as, formation of larger molecule from small reactant, followed by loss of water from the reaction. 
- They are also called condensation reactions. 
a. Explanation: Hydrolysis, it is the reaction in which compound is interacted with water which results in the degradation of that particular compound. 
- Hydo means water, lysis means to dissolve or breakdown.