In the question below, a sentence is given with four words highlighted. These…

In the question below, a sentence is given with four words highlighted. These four words may not be in their correct position. The sentence is then followed by options with the correct combination of words that should replace each other in order to make the sentence grammatically and contextually correct. Find the correct combination of the words that replace each other.

Astronomical (A) temperatures (B) are usually estimated from spectroscopic (C) measurements (D).