P `(vecp) and Q (vecq)` are the position vectors of two fixed points and `R(vecr)` is the postion vector of a variable point. If R moves such that `(vecr-vecp)xx (vecr-vecq)=vec0`then the locus of R is

Options

A. a plane containing the origian O and parallel to two non-collinear vectors `vec(OP) and vec(OQ) `
B. the surface of a sphere described on PQ as its diameter
C. a line passing through points P and Q
D. a set of lines parallel to line PQ

Answer

c

Explanation

`r (vecr)` moves on PQ