R&D

R, or r, is the eighteenth letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ar (pronounced ), plural ars. The letter ⟨r⟩ is the eighth most common letter in English and the fourth-most common consonant, after ⟨t⟩, ⟨n⟩, and ⟨s⟩.