Which can be called a "seastead" according to professor Petrie’s definition
Of the several structures of a seastead, which one is the most expensive

A．All through high school he was interested in being an engineer.
B．While in college, he took an interest and aptitude test and discovered his real talent.
C．He took the testing feedback seriously and became a psychologist.
D．Listening is an essential part of making good decisions in his clinical practice.

A．To find out why people make associations between smell and sound.
B．To find out why people make associations between taste and sound.
C．To find out if there’s a connection between smell and sound.
D．To find out which sound best matches a specific smell.