Why is it often not possible to establish a temporal relationship between exposure and disease with a cross sectional study?

 The correct answer is : Because the temporal relationship between the onset of the disease and the exposure cannot be established, then cross-sectional studies cannot assess the cause-effect relationship.

Explanation:  The cross-sectional study is an observational study that evaluates exposure and outcome at a given time in a population sample.

the federal government of the united states was established by the constitution. us is a presidential republic. the president is head of state, head of government and of a two party legislative and electoral system. the supreme court balances the powers of the federal and the state government. yhe executive branch is headed by the oresident. there are two chambers of congress, the senate and the house of representatives. judicial power is exercised by the judicial branch (or judiciary), comprised of the supreme court and lower federal courts. the judiciary's function is to interpret the   constitution as well as the federal laws and regulations.