Which fabric is a strong cotton material commonly used for making jeans and is typically yarn-dyed blue?

Denim is indeed the correct answer because it is a sturdy cotton fabric specifically known for its use in making jeans. This fabric is typically yarn-dyed blue, which gives it the iconic blue color associated with denim jeans. The weaving technique used in denim, often a twill weave, contributes to its durability and distinctive diagonal ribbing on one side, which enhances its strength and texture.

Canvas, while also a strong fabric, is generally heavier and used for items like tote bags, tents, and shoes rather than jeans. Chinos refer to a style of pants made from a different fabric that is lighter and often used for casual trousers; they are not directly related to jeans. Twill, on the other hand, describes a type of weave pattern that can be used in various fabrics, including denim, but does not specifically denote the fabric itself used for jeans. Therefore, the unique characteristics of denim, particularly its familiar blue hue and strength, make it the most fitting choice for this question.