What invention by eli whitney affected the textile industry?

Cotton Gin.

Explanation:

Eli Whitney, who was an American, invented the Cotton Gin machine that brought the revolution in the textile industry during the Industrial Revolution. The machine was invented in 1794 to make the separation of cotton seeds from the fiber easy and quick.

Whitney applied for the patent for his invention which was approved in 1794.

The one adverse effect of the cotton gin was that it promoted more slavery. Whitney invented cotton gin with the purpose to lower the slavery but there was an inverse effect because the invention of the cotton gin made planters grow more of cotton crops and more plantation required more slaves.

So, the correct answer is cotton gin.