Explanation:

- Let's break down the segments:

- (R) introduces the subject: "The Environment (Protection) Act, 1986 authorizes the central government".

- (Q) details the purpose: "to protect and improve environmental quality".

- (P) adds more specifics: "control and reduce pollution from all sources".

- (S) introduces another action: "and prohibit or restrict the setting and /or operation of any".

- (T) specifies the object of restriction: "industrial facility on environmental grounds".

- Among available options:

- Option 1 (RQPST) isn't logically coherent. It jumps from purpose (Q) directly to pollution control (P) without connecting action.

- Option 3 (RTPSQ) confuses the sequence by placing the prohibition before the integrated purpose and actions.

- Option 4 (RSTPQ) also lacks proper sequence by putting specifics before general actions.

- Option 5 (RQSPT) has R connecting well with Q, then detailing the specific actions (S), and finishing by specifying the object (T).

- Option 2 (QPRST) connects the purpose and actions smoothly:

- R: Introduction

- Q: Purpose

- P: General actions

- S: Additional actions

- T: Specific target

Option 1 (RQPST) is the correct sequence.