Question

In paragraph 5, the term nay-sayers can be defined as -

a
Ob
Od
people who disagree or have negative attitudes.
people who no longer believe in exploring unknown areas.
people who do not like to think that space needs to be explored.
people who are disagreeable with the author's expertise in the frontier.

Answer 1

Answer: people who disagree or have negative attitudes.

Explanation: A "nay sayer" is someone who, basically, says no to everything.