"They want jeans."
Translation:הם רוצים ג'ינסים.
The mark ׳ is called a geresh, encoded in Unicode as U+05F3 HEBREW PUNCTUATION GERESH. Depending on your setup, you may or may not have it on your keyboard, and your operating system may or may not provide an easy way to enter a Unicode code point. For me, using Ubuntu with the Hebrew keyboard, I can type it directly as AltGr+`, or I can press Ctrl+Shift+U and then enter 05F3.
Apparently it is very common to type an apostrophe instead of a geresh because of its absence on many keyboards — so common, in fact, that Duolingo uses an apostrophe (') instead and considers the correct character (׳) an error. I answered “הם רוצים ג׳ינסים.” and was accused of a typo.