When a major car company lowers its prices, other car makers will probably?

The answer is: Other car makers will also lower the price of their cars.

Explanation:

The market for new cars is extremely competitive and very segmented. Car companies are continuously offering new models and technologies, and offering discounts, promotions, low interest car leases, etc.  

For example; Toyota is the number one car seller in the US and its main competitor is probably Honda (since they both sell basically the same types of cars and SUVs). If it decides to offer a Thanksgiving bonus of $2,000 for purchasing a Corolla, then Honda will probably offer the same or a larger bonus for clients that buy Civics. The market is simply too competitive for allowing any promotion go unanswered by the competition.

answer; measurable outcome;

answer; trojan horse;