Which function of x has the least value for the y-intercept

The answer is B

hope this helps

Slope intercept form can be represented with the formal y=mx+3 in which B represents y intercept in case 3 is the y

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads