Indicate If Each of the Following Descriptions Matches Messenger RNAs

Short Answer

Indicate if each of the following descriptions matches messenger RNAs (M), ribosomal RNAs (R), or transfer RNAs (T). Your answer would be a four-letter string composed of letters M, R, and T only, e.g. RRRT.
( ) They contain codons.
( ) They contain anticodons.
( ) They are (covalently) attached to amino acids.
( ) They are at the core of a complex that carries out protein synthesis.