Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
P_QU_V_T_URVPTQ_R_P_QU_V

The given expression can be broken down into repeating cycles or repeating groups of 8 letters.
Total length of the series including blanks =24.
Let us divide the series into 3 groups of 8 letters each:

P _ Q U _ V _ T ∣ _ U R V P T Q _ ∣ R _ P _ Q U _ V
By comparing the blocks with each other:

Comparing block 1 and block 3, we notice the pattern P T Q U R V P T or similar variations.

Let's check the complete pattern: P T Q U R V P T

First group: P [T] Q U [R] V [P] T

Second group: [Q] U R V P T Q [R]

Third group: R [V] P [T] Q U [R] V

Wait, let's look closely at the letters present: P, Q, U, V, T, R.
Let's see the sequence: P T Q U R V P T→ Group 1
Q U R V P T Q R→ Group 2
R V P T Q U R V→ Group 3

Let's re-verify the blanks with Option C:

Blanks: T, R, P, Q, U, V, T, R

Putting them in order:
1st blank: T→PTQU
2nd blank: R→URV
3rd blank: P→VP
4th blank: Q→QURV
5th blank: U→PTQU
6th blank: V→VR
7th blank: T→PTQU
8th blank: R→URV

Let's read the full completed string:

P T Q U R V P T ∣ Q U R V P T Q R ∣ R V P T Q U R V
Notice the shift pattern:

Group 1: P T Q U R V P T

Group 2 starts with Q U, shifting forward.

Group 3 starts with R V, shifting forward.

This matches perfectly with Option C.