Which of the following languages is the product {aⁿb | n>=0} {cⁿ | n >=0}

a. {aⁿb^mcⁿ | n >= 0, m >= 0}

b. {aⁿbc^m | n >= 0, m >=0}

c. {aⁿbcⁿ | n >= 0}

d. {aⁿbⁿcⁿ | n >= 0}