Question

what is the term for a set of rules that specify a style for the selected element in css?
rule set
css declaration
property group
style block

Explanation:

In CSS, a "Rule Set" is a set of rules that specify a style for the selected element. A CSS Declaration is part of a rule set (property - value pair). Property Group is not a standard CSS term. Style Block is also not the correct term for this concept.

Answer:

Rule Set