counter for choices; counter for options
Colloquial counter used for counting choices, options, or alternatives. Often used in contexts like multiple-choice questions or decision-making.
この問題は四択です。
This question has four choices.
三択の中から一つ選んでください。
Please choose one from the three options.
This question has four multiple-choice options.
I'm torn between the two options, A or B.
選択肢 is the noun for an 'option/choice', while 択 is the counter used to count how many such options there are (三択 = three choices).
Derived from the kanji 択, meaning 'choose' or 'select'. The reading たく is the on'yomi. The counter usage is a colloquial abbreviation of 選択肢 (options).