Qaysi qatorda undov sozlarga xos xususiyat notogri berilgan?

A) gap tarkibida kelib, uni undov gapga aylantirishi mumkin
B) undov sozlar ozi undov gap bolib kelishi mumkin
C) undov sozlar gap bilan grammatik jihatdan boglanishi mumkin
D) undov sozlar otlashganda gapda malum vazifada qollanishi mumkin