Select the phrase that best expresses the meaning of the given idiom: Blow hot and cold

The correct option is "To alternate continuously between inconsistent opinions or attitudes".

Explanation:
The idiom "blow hot and cold" means to be unpredictable or changeable in one's mood, enthusiasm, or opinion about something. It describes someone who frequently shifts between strong enthusiasm ("hot") and complete disinterest or indifference ("cold").

Example in a sentence:
"He keeps blowing hot and cold about buying a new car, so we don't know what he will decide."

Breakdown of Options:
• To behave in a consistent and reliable fashion: Incorrect. This is the opposite of blowing hot and cold.
• To maintain emotional stability during successes and failures: Incorrect. This describes emotional composure or equanimity.
• To alternate continuously between inconsistent opinions or attitudes: Correct. This directly captures the essence of the idiom.
• To boast excessively about one's own accomplishments: Incorrect. This refers to bragging or "blowing one's own trumpet."