Correct Answer: B
In the Chinese language, both “只(zhī)” and “支(zhī)” are commonly used measure words which are placed before nouns. However, they should be used with different kinds of nouns.
Firstly, “只(zhī)” is the measure word for most animals, such as “一只猫(yìzhī māo) a cat,” “两只老虎(liǎngzhī lǎohǔ) two tigers,” “几只小鸟(jǐzhī xiǎoniǎo) several birds,” etc.
Linda: Nǐ xǐhuan xiǎo dòngwù ma?
Linda：你 喜欢 小 动物 吗？
Linda: Do you like small animals?
Wáng Míng: Xǐhuan. Wǒ jiā lǐ yǎng le liǎngzhī māo hé wǔzhī xiǎoniǎo.
王 明： 喜欢。 我 家 里 养 了 两只 猫 和 五只 小鸟。
Wang Ming: Yes, I like them. I have two cats and five birds at home.
Nà zhī xiǎo tùzi zhēn kěài!
那 只 小 兔子 真 可爱！
That little rabbit is so cute!
Additionally, “只(zhī)” can be also used with some appendages of the body, such as “一只手(yìzhī shǒu) one hand,” “两只耳朵(liǎngzhī ěrduo) two ears.” “一只脚(yìzhī jiǎo) a foot,” and so on.
Tā de yìzhī shǒu shēnjìn le shàngyī kǒudài.
他 的 一只 手 伸进 了 上衣 口袋。
One of his hands went down into his coat pocket.
Zuówǎn méiyǒu shuì hǎo, yǒu yìzhī yǎnjing zhǒng le.
昨晚 没有 睡 好， 有 一只 眼睛 肿 了。
I didn’t sleep well last night, because one of my eyes was swollen.
As a measure word, “支(zhī)” can be used with long, thin, inflexible objects, such as “一支香烟(yī zhī xiāngyān) a cigarette,” “两支笔(liǎngzhī bǐ) two pens,” “五支匕首 (wǔzhī bǐshǒu) five daggers,” etc.
Lǎopo: Nǐ zěnme yòu zài chōuyān? Nǐ yǐjīng chōu le wǔzhī xiāngyān le!
老婆： 你 怎么 又 在 抽烟？ 你 已经 抽 了 五支 香烟 了！
Wife: Why are you smoking again? You have already smoked five cigarettes!
Lǎogōng: Qīnàide, zhè shì zuìhòu yìzhī.
老公： 亲爱的，这 是 最后 一支。
Husband: This is the last one dear.
Wǒ de wénjùhé lǐ yǒu wǔzhī qiānbǐ.
我 的 文具盒 里 有 五支 铅笔。
There are five pencils in my pencil box.
“支(zhī)” can also be used with words related to the military, like “一支部队(yìzhī bùduì) an army,” “两支海军(liǎngzhī hǎijūn) two navies,” etc. Or it can be used with songs and dances, such as “一支歌曲(yìzhī gēqǔ) a song,” “几支舞(jǐzhī wǔ) several dance,” and so on.
Nà zhī duìwu zhēn zhěngqí!
那 支 队伍 真 整齐！
The troops are so orderly!
Wǒ kěyǐ qǐng nǐ tiào dìyì zhī wǔ ma?
我 可以 请 你 跳 第一 支 舞 吗？
May I have the first dance with you?
In our test, pen should be used with “支(zhī),” so the answer is B.