A result that is most likely to give a financial manager concern that his firm’s credit policy may have become too lenient is.（）

A. inventory turnover has decreased considerably. 

B. accounts receivable as a percentage of sales has decreased. 

C. weighted average collection period has increased.

于某，男，68岁，农民，种地为生，现住农村老家，老伴在三年前去世了，有一儿子，大学毕业后留在了城里工作。老人年岁高，走路不太灵活，除了夏天在小院子里种点小菜以外，平时很少外出，耕地也包出去了。儿子很孝心，多次劝说老人到城里与他一起生活，但老人说什么也不去，说住城里不习惯，也帮不上儿子的忙，只会给儿子带来麻烦，打扰儿子的生活。老人每天没事可做，多半时间都孤单地坐在院子里。

[问题]

结合案例来说明老年人都会遇到哪些具体问题。