Select the option that can be used as a one-word substitute for the given group of words.
An instrument for viewing distant objects in space.

Correct option is C

The correct one-word for the given group of words is telescope.
Explanation: A telescope is an optical instrument designed to make distant objects appear nearer by magnifying them through lenses or mirrors. (Hindi: दूरबीन)
Example: Scientists use telescopes to observe celestial bodies in space.
Meanings of the given other options:
· Microscope: An instrument for viewing very small objects (Hindi: सूक्ष्मदर्शी)
· Spectrograph: A device used to record spectra (Hindi: वर्णक्रम ग्राफ़)
· Binoculars: An optical instrument for viewing distant objects with both eyes (Hindi: दूरबीन)