Allegations outside Thomas's knowledge should be dealt with as non-admissions, requiring Lucy to provide strict proof. Although the burden of proof lies with Lucy, Thomas should not blanket deny everything as it implies he has knowledge of all facts (making Options A and C incorrect), nor should he ignore any allegations made (making Option B incorrect). Option E is incorrect because it suggests that Thomas denies all allegations, which does not align with him admitting some and denying others. 

Key Point: Defendants should use non-admissions for allegations outside their knowledge, requiring claimants to provide proof, and properly address each allegation based on their knowledge.