甲乙丙丁涉嫌犯罪被立案侦查，后根据案件具体情形，分别对甲乙丙丁采取监视居住强制措施，下列对于监视居住的地点说法正确的是（）。

A、丁涉嫌间谍罪，在指定的居所监视居住，由人民检察院监督监视居住的执行正确选项

B、丙涉嫌参加恐怖组织罪，在当地有固定住所，但公安机关认为在其住所有碍侦查，执行机关指定居所监视居住

C、甲涉嫌盗窃罪，在当地有固定住所，但公安机关认为不宜与其同案犯妻子同住一起，便指定居所对甲监视居住

D、乙涉嫌受贿罪，在当地没有固定住所，由公安机关指定居所执行监视居住

Another critical factor that plays a part in susceptibility to colds is age. A study done by the University of Michigan School of Public Health revealed particulars that seem to hold true for the general population. Infants are the most cold-ridden group, averaging more than six colds in their first year. Boys have more colds than girls up to age three. After the age of three, girls are more susceptible than boys, and teenage girls average three colds a year to boys’ two.
The general incidence of colds continues to decline into maturity. Elderly people who are in good health have as few as one or two colds annually. One exception is found among people in their twenties, especially women, who show a rise in cold infections, because people in this age group are most likely to have young children. Adults who delay having children until their thirties and forties experience the same sudden increase in cold infections.
The study also found that economics plays an important role. As income increases, the frequency at which colds are reported in the family decreases. Families with the lowest income suffer about a third more colds than families at the upper end. Lower income generally forces people to live in more cramped quarters than those typically occupied by wealthier people, and crowding increases the opportunities for the cold virus to travel from person to person. Low income may also adversely influence diet. The degree to which poor nutrition affects susceptibility to colds is not yet clearly established, but an inadequate diet is suspected of lowering resistance generally.

What does the author claim about the study discussed in the passage

A．It contains many inconsistencies.
B．It specializes in children.
C．It contradicts the results of earlier studies in the field.
D．Its results apparently are relevant for the population as a whole.