题目

Many of us like to relax with a box set and a bag of crisps. But eating while watching TV or looking through Facebook can cause people to overeat, leading to obesity(肥胖), a new study has found. And parents being distracted（注意力不集中的） means they do not pay attention to their children at the dinner table, so they don’t learn healthy habits such as stopping eating when full. Researchers said so-called “distracted dining” may be as dangerous to health as losing concentration(专心) on a motorway. The US researchers studied 60 families during mealtimes to test the 如图，从点P引出的几条线段中，最短的一条线段是（　　）A．PAB．PBC．PC