Should
career selection should be based on salary alone.

I love this question.

In essence, career selection should NOT be based on salary alone.

Career selection should include one's likes, abilities, education and experience. After those are determined or assessed then salary can be factored into the equation of employment.
Notice the word CAREER: this is something that is not temporary but a lifelong pursuit of work in a field one enjoys & is good at accomplishing.

Answer the car approaching from the right has the right of way;

The answer is b. a pro-natalist