Correct Answer: obviously

Solution : The correct choice is the fourth option.

Amazingly implies a sense of wonder or surprise, indicating that something is extraordinary or exceptional.
Obviously, on the other hand, it suggests that something is easily perceived, apparent, or evident without the need for surprise or astonishment.

The meanings of the other words are:

• Shockingly: It means in a manner that causes surprise, disbelief, or a strong reaction; unexpectedly.
• Unusually: It means in a manner not commonly seen or experienced; out of the ordinary.
• Astonishingly: It means in a manner that causes great surprise or amazement; remarkably.

So, obviously serves as the antonym for amazingly in this context, indicating a lack of surprise or wonder.