Correlation feature selection followed by regression
I think this is a case for linear regression with a lasso/ridge penalty. The lasso/ridge does „shrink“ features/variables, so that it is easy to see which features are important. Since you have 100 variables, you could opt for lasso, since lasso can also „automatically“ exclude features. Here is a lasso example in Python: https://datascience.stackexchange.com/a/53639/71442.