I think it is ‘the pension’ especially when the grant of a pension is a life-long benefit. But I wonder why the speaker does not use the definite article with Sick Pay and Health Insurance which are also permanent in nature.
I don’t see any reason to use a definite article in this sentence. There are times when a definite article is called for, but I don’t think this is one of them.
An article for “sick pay” or “health insurance” doesn’t work at all. Although “a health insurance plan” works.