Indicate if each of the following descriptions matches actin filaments (A), microtubules (M), or intermediate filaments (I). Your answer would be a four-letter string composed of letters A, M, and I only; e.g. AAMM.
( ) They form hollow structures with multiple lateral interactions.
( ) They form strong structures that are more resilient than the other two cytoskeletal filaments.
( ) Their subunits bind GTP and hydrolyze it.
( ) They form coiled-coil interactions between the subunits.