This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: During the Middle Ages, the Eritrea region was known as Medri Bahri ("sea-land"). The name Eritrea is derived from the ancient Greek name for Red Sea ( Erythra Thalassa, based on the adjective erythros "red"). It was first formally adopted in 1890, with the formation of Italian Eritrea (Colonia Eritrea). The territory became the Eritrea Governorate within Italian East Africa in 1936. Eritrea was annexed by Ethiopia in 1953 (nominally within a federation until 1962) and an Eritrean Liberation Front formed in 1960. Eritrea gained independence following the 1993 referendum, and the name of the new state was defined as State of Eritrea in the 1997 constitution.[citation needed]
What was the Roman name for the Red Sea?