‘S’ will be the first part of the given sequence as ‘this happens’ is used in the context of ‘mother may die’ mentioned in the very opening sentence. It will then be followed by ‘R’ which states that when many sheep give birth to lambs at the same time which results in the weak structure of the new born lambs. ‘P’ will follow next as it talks about the after effects, that is, motherless lambs and sheep without lambs. ‘Q’ will pair with S6 as ‘this natural tendency’ is used in connection to‘will not feed or look after a motherless Iamb’. Hence, SRPQ is the correct sequence. Thus, option (d) is correct.