Even before my father left us, my mother had to go back to work to support our family. Once I came out of the kitchen, complaining, "Mom, I can't peel(......) potatoes. I have only one hand." Mom never looked up from sewing. "You get yourself into that kitchen and peel those potatoes," she told me. "And don't ever use that as an excuse for anything again!" In the second grade, our teacher lined up my class on the playground and had each of us race across the monkey bars, swinging from one high steel rod to the next. When it was my turn, I shook my head. Some kids behind me laughed, and I went home crying. That night I told Mom about it. She hugged me, and I saw her "we'll see about that" look. The next afternoon, she took me back to school. At the deserted playground, Mom looked carefully at the bars. "Now, pull up with your right arm," she advised. She stood by as I struggled to lift myself with my right hand until I could hook the bar with my other elbow . Day after day we practiced, and she praised me for every rung I reached. I'll never forget the next time, crossing the rungs, I looked down at the kids who were standing with their mouths open. One night, after a dance at my new junior high, I lay in bed sobbing. I could hear Mom come into my room. "Mom," I said, weeping, "none of the boys would dance with me." For a long time, I didn't hear anything. Then she said, "Oh, honey, someday you'll be beating those boys off with a bat." Her voice was faint. I peeked  out from my covers to see tears running down her cheeks. Then I knew how much she suffered on my behalf . She had never let me see her tears. Which of the following expressions can be used most suitably to describe Mom's attitude when she made the child to peel potatoes?
Cruel. Serious. Cold. Strict