Answer: B
In triangles AOP and QOB: \(\angle\)AOP = \(\angle\)QOB [both are right angles] \(\angle\)OAP = \(\angle\)OPB [both are angles subtended by arc PB] ∴ Triangles AOP and QOB are similar. ∴ \(\cfrac{OP}{OB} = \cfrac{OA}{OQ}\) i.e., \(\cfrac{4}{2} = \cfrac{8}{OQ}\) ⇒ \(OQ = 4\) So, OQ = 4 cm.
In triangles AOP and QOB: \(\angle\)AOP = \(\angle\)QOB [both are right angles] \(\angle\)OAP = \(\angle\)OPB [both are angles subtended by arc PB] ∴ Triangles AOP and QOB are similar. ∴ \(\cfrac{OP}{OB} = \cfrac{OA}{OQ}\) i.e., \(\cfrac{4}{2} = \cfrac{8}{OQ}\) ⇒ \(OQ = 4\) So, OQ = 4 cm.