Since chronic stress can ____________ the immune system, making individuals more susceptible to illness and ____________ their overall well-being, healthcare practitioners often recommend mindfulness practices and proper sleep to____________ these negative effects.

The sentence explains how chronic stress harms health and why certain remedies like mindfulness and sleep are suggested. The blanks must describe how stress negatively affects the immune system and overall well-being, and how these effects can be reversed or managed.

The first blank should use a word that implies the meaning that chronic stress has a negative effect on health. This part tells us what chronic stress does to the immune system, so we need a verb that means to weaken or damage. For the second blank, we’re continuing the negative effects of stress — it harms overall well-being, so the word should again reflect harm or reduction. For the third blank, we shift to solutions. The sentence talks about what mindfulness and sleep do — so this blank needs a verb that means to fight back or lessen the negative effects.

Of the choices given, the best choice is Option B:[compromise; impair; counter], because "compromise" means to weaken, which fits perfectly with how stress affects the immune system. "Impair" means to damage or reduce, which suits the idea of declining well-being. "Counter" is the right word to describe how mindfulness and sleep help fight back against those negative effects. 

Option A:[Undermine; elevate; impede] is contradictory, as "elevate" means to improve, which doesn’t fit with the idea of harm. Option C:[Paralyse; improve; diminish] makes no sense since "improve" is a positive word where a negative one is needed.Option D:[Endanger; preserve; decrease] also conflicts because "preserve" doesn’t match the context of harm. Only option A logically and clearly completes the sentence.

The correct choice is therefore Option A.