I need help with this quiz

Can someone check my answer? you : )

Which expression shows the sum of the polynomials with like terms grouped together

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample