to blunder or get into a scrape is correct because put one's foot in it means to say or do something foolish, embarrassing, or troublesome.

This idiom or phrase is useful because it helps students understand the intended meaning beyond the individual words.

Examples: I put my foot in it when I forgot her name. He put his foot in it by criticizing the plan in front of the manager.

The phrase describes an embarrassing mistake, not payment, loyalty, power, or vanity.