For the two studies below, what is the study design and two reasons why you know its that study design.

 A$)$a study was conducted to determined if serum vitamin d levels were linked to hip fractures. a group of hospitalised patients newly diagnosed with hip fractures together with a group of healthy adults in communities were recruited. serum vitamin d levels were assessed among all participants

. B$)$ a study compared the changes in age$-$standardised lung cancer mortality rates $($per $100,000$ population$)$ by sex from $1945$ to $2020,$ and the prevalence of daily smoking by sex, $1964-2019.$