<u>Answer:</u>
In this context the verb meet means <u>to see and talk to someone for the first time</u>, which in spanish is <em>conocer</em> (to have a notion or idea of someone from the first impression).
In this sentence the verb is in past tense (met) and we have the <u>time adverb </u>yesterday.
So, the spanish verb <em>conocer</em> must be conjugated in past tense, taking into account the subject of the sentence <em>yo</em> (I):
<h2>
Yo conocí</h2>
Therefore, the right answer is:
<h2>Yo <u>conocí</u> a Luisa ayer.</h2>
