I’m not a lawyer and I hope they get this bitch — but it does seem like a person ought to be able to take the 5th on some questions and answer others...presuming they only feel that some of them potentially incriminate themselves.
Choosing only certain questions to avoid by taking the 5th would lead to assuming guilt on those questions, something the invocation is trying to avoid.
Can’t imagine a lawyer telling a client to pick and choose.