Hello!
J'aime le football [blank] je n'aime pas le baseball translates to "I like soccer [blank] I do not like baseball".
The options translate as follows:
mais - "but"
beaucoup - "a lot"
aussi - "also"
un peu - "a little bit"
The option that makes the most sense here is mais: "I like football but I do not like baseball."
Answer:
mais
