Should tester be included in refining PBI?

Dear all,

An open assessments' question:
Programmers and testers SHOULD NOT be included in refining Product Backlog items.
Ans: False.

If the question is altered to:
Programmers and testers SHOULD be included in refining Product Backlog items.
True or False?

True. The Scrum Team is cross-functional. It needs both programming and testing skills for PBI refinement,
False: There is no tester role in Scrum Team.

How to choose?