Option 1 -> Obscure means unclear or difficult to understand, which is similar to esoteric, not opposite.
Option 2 -> Accessible means easy to understand or approach, available to everyone - the opposite of esoteric.
Option 3 -> Uncertain means not sure or doubtful, which doesn't relate to the concept of being specialized or restricted.
Option 4 -> Antiquated means old-fashioned or outdated, unrelated to whether something is esoteric or not.
Hence, Option 2: Accessible -> Esoteric refers to knowledge intended for or understood by only a select few with specialized understanding, while accessible means readily available and understandable to the general public -> correct