The correct plural form of ‘spectrum’ is— ?

The correct plural form of ‘spectrum’ is ‘spectra’ (option B), derived from Latin where many English scientific terms find their roots. In Latin, many nouns that end in “-um” change to “-a” in their plural forms. Thus, ‘spectrum’ (meaning a broad range or a distribution of something, particularly in scientific contexts like physics or biology) becomes ‘spectra’ when referring to multiple ranges or distributions.

The other options are incorrect. Option A, "Spec trum," is simply a misspelling or incorrect division of the word. Option C, "species," refers to a group of organisms capable of interbreeding, and does not relate to ‘spectrum.’ Option D, "imagery," pertains to visual representations and is unrelated to the concept of spectrum.

Understanding these grammatical rules helps clarify not just the correct usage of ‘spectra,’ but also aids in recognizing how Latin-derived terms are adapted in English, making it easier to navigate similar pluralizations in scientific language.