Which of the following is a brand name for Aspirin?

Ecotrin is indeed a brand name for Aspirin. Aspirin is a widely used medication that acts as an analgesic (pain reliever), antipyretic (fever reducer), and anti-inflammatory agent. It is commonly used for pain relief, reducing fever, and preventing blood clots. The brand name Ecotrin specifically refers to a formulation of Aspirin that is often marketed as being gentler on the stomach, as it is enteric-coated to minimize gastrointestinal irritation, a common side effect associated with standard Aspirin.

The other options provided do not relate to Aspirin. Proventil is a brand name for the medication albuterol, which is used to treat asthma and other conditions involving difficulty breathing. Lasix is the brand name for furosemide, a diuretic used to treat fluid retention and high blood pressure. Xanax is a brand name for alprazolam, which is primarily prescribed for anxiety and panic disorders. Each of these medications serves very different purposes and thus is not associated with Aspirin.