Which one of the following factors generally indicates a favorable prognosis for

Which is a limitation of experimental research as an approach to knowledge?

(a) subjects are often assigned randomly, which makes statistical analysis difficult (b) subjects are often assigned randomly, so it is difficult to draw cause-and- effect inferences (c) alternative explanations are made less likely (d) the groups are made pretty much equal, to start with (e) there is often an inadequate attempt to have more than one situation in an investigation, even though there are typically many subjects

For many couples, communication about sex is often hampered by

a. inexperience with discussing sex b. belief in stereotypic gender roles c. power differences in the relationship d. all of the above