Can someone help resolving this and explain? thank you

Assume that there are 8 overpriced securities and 4 underpriced securities on the market. What type of position do you take (among the following) to get an advantage out of this information?

a) you invest in the 4 underpriced securities

b)short sale the 8 overpriced securities

c)invest in the most 2 overpriced

d)invest in 4 underpriced and you short sale 8 overpriced

e)invest in the most 2 underpriced and short sale the 2 most overpriced