Fill in the blanks:
The scientist’s groundbreaking discovery opened ___ to new possibilities and set ___ for further research.

Correct option is B

The correct option to fill in the blank is (b) doors, trends.
Explanation:
· Opened doors – metaphor meaning “created new opportunities” (नए अवसर खोलना)
· Set trends – to start new ideas or movements that others follow (नए चलन की शुरुआत करना)
Why this fits: Scientific discoveries often lead to future exploration and start new directions. This pairing best conveys the intended idea of progress and innovation.
Grammatical Rule (English): Idiomatic collocations should match logically — "open doors to opportunities" and "set trends" are commonly paired structures.
Grammatical Rule (Hindi): “Open doors” का अर्थ है नए रास्ते या अवसर खोलना और “set trends” का अर्थ है चलन की शुरुआत करना।
Meanings of the other options:
· (a) Windows – openings (खिड़कियाँ), restrictions – limitations (पाबंदियाँ) – contradictory.
· (c) Pathways – routes (मार्ग), barriers – obstacles (रुकावटें) – cancel each other out.
· (d) Valves – controls flow (वाल्व), rules – regulations (नियम) – scientifically inconsistent here.