Answer: Conozcamos a los Secord is correct because "los Secord" is a familiar unit.
Step-by-step explanation:
Transitive verbs are those that need a direct object to complete their meaning. In Spanish there are some transitive verbs (buscar, conocer, ver, visitar) that depending on if the object is inanimate (a thing) or animate (a person/animal), the verb works a bit different.
If the direct object is a thing, there is not a preposition between the verb and the direct object, instead if the direct object is a person or an animal, then the verb needs the preposition "a" before the direct object. This is why it is called personal "a".
Since a family unit are people, then the verb needs the preposition "a" before the direct object.
Spymore