The correct answer is Yes; one angle in ∆ABC is congruent to one angle in ∆DEF.
Here's why the other options are incorrect:
Yes; two angles in ∆ABC are congruent to two angles in ∆DEF: This is incorrect because only one pair of angles has been identified as congruent in the given information.
No; only one angle in ∆ABC is congruent to one angle in ∆DEF: This is also incorrect because the statement claims that there is only one congruent angle, while the information provided identifies two congruent angles (18°).
No; none of the angles in ∆ABC are congruent to any angles in ∆DEF: This is incorrect because the information explicitly states that one angle in each triangle is congruent (18°).
Therefore, based on the given information, only one angle in ∆ABC is congruent to one angle in ∆DEF.