Read the sentences from the "Ellis Island Oral History Project" excerpt.

However when I started school in Chicago, where I grew up, needless to say, first of all, I couldn't speak a word of English, and I was the only child in the school that couldn't speak English. And (she laughs) it wasn't too happy the first couple of years but my mama said, "Take heart because some day you're going to be able to speak two languages and all the ones that were teasing you will speak only one." And it was true.

What is one central idea of the sentences?

a. Some immigrants lived in Chicago.
b. Chicago's teachers did a good job of teaching English.
c. Learning English was important.
d. It took about two years to learn to speak English.