Answer:
The - defined article
The survival of hibernating frogs in freezing temperatures - subject
is - verb
Step-by-step explanation:
In this example, we have a sentence whose subject is a noun phrase the survival of hibernating frogs in freezing temperatures. The main verb is SURVIVAL, the is a determiner and of hibernating frogs in freezing temperatures is a postmodifier. As this noun phrase is singular (the survival), the verb will agree in person and gender (third person singular of the verb "to be" = is).