The correct option is
A 3.6 cm
Since
PQ∥AB, we have the triangles
ABC and
PQC congruent to each other, as the angles formed are the same.
Since the two triangles are congruent, the ratio of corresponding sides will be the same.
Thus ABPQ=BCQC
⇒ABPQ=BQ+QCQC
⇒6.3PQ=4.8+3.64.8
⇒PQ=3.6 cm