Concept:Vertically opposite angles are equal, and the sum of the angles in a triangle is 180∘.Explanation:The two straight lines intersect at R.So, ∠TRS and ∠PRQ are vertically opposite angles.Therefore, ∠PRQ=40∘.In △PQR, we have:∠QPR=68∘ and ∠PRQ=40∘.Using the angle sum of a triangle:∠QPR+∠PRQ+∠PQR=180∘.68∘+40∘+∠PQR=180∘.108∘+∠PQR=180∘.∠PQR=180∘−108∘=72∘.Answer:∠PQR=72∘, so the correct option is C.