Today, the ancient art form has found a new 17 in the hands of contemporary artists.
答案：(B) application
語意「這個古老藝術形式在當代藝術家手中找到了新的『應用方式』」，application（應用）符合；competition（競爭）、investigation（調查）、participation（參與）都不合。
application 你腦中第一個跳出來的一定是「申請」——application form（申請表）、apply for a job（應徵工作）。所以看到 found a new application 會覺得奇怪：藝術形式怎麼會「找到新的申請」？這就是印象與用法的落差。apply 這個字有三條常考的線：apply for（申請）、apply to（適用於）、apply A to B（把 A 應用／塗抹於 B）。名詞 application 對應的是後兩者，意思是應用、用途。
句子是 Today, the ancient art form has found a new ___ in the hands of contemporary artists（今日，這門古老藝術在當代藝術家手中找到了新的 ___）。主詞是 the ancient art form（一種技藝），一種技藝能「找到新的」什麼？只能是新的用法。後面整段就是在說明這個新用途：Henna Heals 這個團體把指甲花刺青畫在癌症病友的光頭上，幫助她們重建自信——古老技藝＋全新用途，這正是 find a new application。
competition（競爭）：文章沒有提到任何競爭關係；investigation（調查）用在案件或研究上，藝術形式不會「找到新的調查」；participation（參與）是抽象的參加行為，find a new participation 語意不通——雖然最後一句提到參與的藝術家人數增加，但那是 artists involved，不是這個空格要填的東西。
find a new application（找到新的用途）、practical application（實際應用）、apply for a job（應徵工作）、apply to sb／sth（適用於……）、apply A to B（把 A 應用／塗抹於 B）、applicant（申請人）。
The art and tradition of using all-natural paste from the henna plant to create temporary henna tattoos goes back to ancient Asia and the Middle East. Over the centuries, henna tattoos 16 used in weddings and holiday celebrations because they are thought to carry blessings from the gods.
Today, the ancient art form has found a new 17 in the hands of contemporary artists. Henna Heals, an artist group based in Canada, uses henna tattoos to help women suffering from cancer feel confident and beautiful again. They draw elegant henna crowns on the women's bare heads to help them 18 the loss of their hair after cancer treatment.
Featuring floral patterns, religious symbols, and messages of hope, the painted henna crowns are amazing substitutes for the hats and wigs that the cancer patients would 19 use to cover their heads. Many women report that the henna crowns really work as a healing device, helping them build a more 20 self-image at a time when they are vulnerable and depressed. According to Frances Darwin, founder of Henna Heals, the number of artists now involved in the project across Canada and the US has grown to over 150.