A researcher records the amount of time (in minutes) that parent child pairs spend on social networking sites to test whether they show any generational differences. From the following findings in APA format, interpret these results by stating the research design used (repeated measures or matched pairs), the sample size, the decision, and the effect size.

Parents spend significantly less time on social networking sites compared their children (MD = -42 minutes), t(29) = 4.021, p < .05, d = 0.49.

(a) What research design was used? (Repeated measures or matched paires?)
(b) What is the sample size? (n = ?)
(c) What is the decision? (Retain or reject the null?)
(d) Based on the estimated Cohen's d, d = 0.49, what is the effect size? (Medium, Large, Small, or Trivial?)