What is the farmer unsure about?

Which development most aided explorers in their ability to set sail the oceans to discover the new world during the age discovery? a. waterproof sails b. the printing press c. map-making devices d. fictional travel accounts

Ayudenme a ordenar esta oracion interrogativa en ingles sandro and bertha / study english / at school.

What does the speaker do in the beginning of her speech that conveys she is a credible, reliable speaker