What name is given to a knit created using only a single thread?

The correct choice is Single knit. A single knit is created using a single thread of yarn, making it a basic form of knit fabric. This type of knit is formed by a series of interlocking loops, all derived from one strand of yarn, which results in a fabric that is typically lighter and more flexible compared to other types of knit structures.

Yarn knit refers to knitted fabric in general but doesn't specifically denote the use of a single thread. Weft knit indicates a method of knitting where the yarn runs horizontally across the fabric, but it can involve multiple threads and types of stitches, making it different from single knit. Twist knit, while a valid term in knitting, specifically involves twisting the yarns together and does not pertain to the single-thread construction of a single knit.

Therefore, the distinction of single knit is important, as it directly relates to the use of one continuous thread, thereby defining the texture and characteristics of that particular type of knit fabric.