True or False? An active-control trial is the best option for researchers hoping to test a newly devised therapy for a life-threatening illness among individuals with the illness, when a previously devised treatment is available for the illness.

Lead time bias is best described as   a. an apparently lower survival rate among persons screened compared to an unscreened group   b. a similar survival time for persons identified during a screening program relative to persons who are diagnosed by clinical symptoms   c. an apparently longer survival time among persons identified during a screening program because they were identified at an earlier stage of their disease   d. a truly longer survival time for persons identified during a screening program because they were given an effective treatment

i found this past paper online and am using it for revision but i cannot find the mark scheme anywhere online. B2 Examples of intra-subject scatter plots between nystagmus intensity and BCVA with best-fit lines are shown in figure 3C for examples of individuals with grades 1 to 4 foveal hypoplasia. Slopes for the best-fit lines for each participant in which the r value were greater than 0.25 are shown in figure 3D. A positive slope predicts that reducing nystagmus improves BCVA. ii. What statistical parameters are generated by this approach and what do they mean?

True or false?  The goal of randomization in RCTs is to make the treatment and control groups similar on all factors except the exposure. True False