The sentence given in our book is as follows,
More important than winning is developing the ability to work with others and developing leadership skills
We are supposed to find where the mistake is in the sentence... 4 options are given ( which I have made bold ) and one of them is correct ( meaning the mistake is there ).. As per the key given in our book, the correct answer is B option i.e. "is" and the key says that "are" should be used here... I am confused and can't understand why should "are" be used here? Anyone who can help me here, please?