Which sentence is expressed correctly?

Which sentence is expressed correctly?
 A) Three countries: US, Japan, and China, have the world's highest GDPs.
 B) Three countries--US, Japan, and China--have the world's highest GDPs.
 C) Three countries; US, Japan, and China; have the world's highest GDPs.

Ques. 2

Businesses use podcasting for sending audio and video messages that do not require a live presence yet offer a friendly human face.
  Indicate whether the statement is true or false

Ques. 3

Which sentence is expressed correctly?
 A) Thirty-eight of our employees were semiretired.
 B) Thirty eight of our employees were semi-retired.
 C) Thirty eight of our employees were semiretired.

Ques. 4

Podcasting has experienced large growth and has spread among various user groups online.
  Indicate whether the statement is true or false

Ques. 5

Which sentence is expressed correctly?
 A) Each seminar participant completed a communication selfevaluation.
 B) Each seminar participant completed a communication self-evaluation.
 C) Each seminar participant completed a communication self evaluation.

Ques. 6

The top digital media device being used to disseminate information today is podcasts.
  Indicate whether the statement is true or false