Last week, an interior designer earned a total of $ 1,258 from consulting for x hours

Choice A is correct. It's given that $68x+85y=\mathrm{1,258}$ represents the situation where an interior designer earned a total of $\$\mathrm{1,258}$ last week from consulting for $x$ hours and drawing up plans for $y$ hours. Thus, $68x$ represents the amount earned, in dollars, from consulting for $x$ hours, and $85y$ represents the amount earned, in dollars, from drawing up plans for $y$ hours. Since $68x$ represents the amount earned, in dollars, from consulting for $x$ hours, it follows that the interior designer earned $\$68$ per hour consulting last week.

Choice B is incorrect. The interior designer worked $y$ hours, not $68$ hours, drawing up plans last week.

Choice C is incorrect. The interior designer earned $\$85$ per hour, not $\$68$ per hour, drawing up plans last week.

Choice D is incorrect. The interior designer worked $x$ hours, not $68$ hours, consulting last week.