"Consider the following statements : Social demography focuses on the relationships among 1. the size and spatial distribution of a population. 2. the age and sex composition 3. the types and forms of social structures such as clans, families and extended kinship groups. 4. the forms or structural features of social institutions Which of these statements are correct? (a) 1 and 4 (b) 1, 2 and 3 (c)" . . . .