Math Help - 2 basic stats questions

Hi I was wondering if somebody could help me with these 2 questions:

17) A colleague comes to you with data they have collected for a research project they have been conducting. they have four sets of data recording the weights of rabbits fed with different feed aditives. initially they just wish to know if there is a significant difference between sets of data. you would advise them to:
perform an ANOVA
ask someone else
undertake regression analysis

18) their initial anaylsis shows that there is a significant difference between the sets of data. you therefore suggest they follow up this analysis with:
T-tests
Correlation
a cup of coffee
ANOVA

I do not fully understand, so if possible, if somebody has any spare time to maybe briefly explain aswell.

thanks

17.
I would perform a one-way anova since a One-way ANOVA is used to test for differences among two or more independent groups. and we essentially have independent groups and since there are four groups so t test would be complicated.

18.
Correlation. since we already know that different additives effect the rabbits, and this suggests some correlation