ATX Past exam question- confused by one part of it? Degrouping charge

Currently doing the kaplan exam kit (Question 1). Gail and brad.

The question is regarding the degrouping charge following the sale of business it mentions that the sale of the intangible fixed asset would normally result in a degrouping charge for the intra group transaction (within 6 years) but because of the the Substantial share exemption this will not apply.

a) I don’t really understand this? Does SSE always mean no degrouping charges apply.

b) it also doesn’t mention any degrouping charge of the Simpson Building disposed of prior disposing of the shares- if the disposal happens prior disposal of shares and so asset has left company I assume this means no degrouping charges apply?