**Core Concept**
Undescended testis, also known as cryptorchidism, is a congenital condition where one or both testes fail to descend into the scrotum. This condition can lead to various complications due to the abnormal environment of the undescended testis, which may not provide the optimal temperature for testicular development and function.

**Why the Correct Answer is Right**
The correct answer is related to the fact that undescended testis increases the risk of several complications, including testicular cancer, infertility, and torsion. This is because the undescended testis is exposed to higher temperatures, which can lead to abnormal cell growth and increased risk of malignancy. The abnormal development of the testis can also lead to impaired spermatogenesis and reduced fertility.

**Why Each Wrong Option is Incorrect**
* **Option A:** Testicular cancer is a known complication of undescended testis, making this option incorrect.
* **Option B:** Infertility is also a well-established consequence of undescended testis, so this option is incorrect as well.
* **Option C:** Torsion is a possible complication of undescended testis, especially in the first few months of life, making this option incorrect.

**Clinical Pearl / High-Yield Fact**
It's essential to note that early surgical intervention, such as orchiopexy, can significantly reduce the risk of complications associated with undescended testis.

**Correct Answer: C. Torsion**