Problem: The Chronicles of Thomas Covenant is a series of ten high fantasy novels written by American author Stephen R. Donaldson. The series began as a trilogy, entitled "The Chronicles of Thomas Covenant, the Unbeliever". This was followed by another trilogy, "The Second Chronicles of Thomas Covenant", and finally a tetralogy, "The Last Chronicles of Thomas Covenant".

Based on the paragraph above can we conclude that "A tetralogy is a series of four books."? OPTIONS:
- Yes
- It's impossible to say
- No

A: It's impossible to say

Problem: Phase contrast magnetic resonance imaging (PC-MRI) is a specific type of magnetic resonance imaging used primarily to determine flow velocities. PC-MRI can be considered a method of Magnetic Resonance Velocimetry. Since modern PC-MRI is typically time-resolved, it can also be referred to as 4D imaging (three spatial dimensions plus time).

Based on the paragraph above can we conclude that "The following words, such as magnetic, resonance, phase, imaging, and contrast, each represent one of the letters in the acronym "PC-MRI". "? OPTIONS:
- Yes
- It's impossible to say
- No

A: Yes

Problem: The Royal Irish Rangers (27th (Inniskilling), 83rd and 87th) was a regular infantry regiment of the British Army with a relatively short existence, formed in 1968 and later merged with the Ulster Defence Regiment in 1992 to form the Royal Irish Regiment.

Based on the paragraph above can we conclude that "The British Army uses the The Royal Irish Regiment on the front lines."? OPTIONS:
- Yes
- It's impossible to say
- No

A:
It's impossible to say