Select the appropriate option to improve the bracketed part of the given sentence.
"The foreign minister said that maintaining cordial relations with our neighbor (becomes the key)."

The correct answer is "is the key."
Detailed Grammar Explanation:
· "Becomes" is incorrect because the subject "maintaining cordial relations" is a gerund phrase (acting as a singular noun).
· The correct verb form is "is" because we describe a state, not a change.
Correction:
· "The foreign minister said that maintaining cordial relations with our neighbor is the key."
Example
· "Hard work is the key to success."