The few candidates that were attracted to this question failed to articulate the required points, thereby losing ample marks.

Some of these answers are:

RECORDER
(a)        -     both have same tonguing;
                        -     both are blown gently;
                        -     both require good breath control;
                        -     both have cross fingering;
                        -     both have half covering of some holes;
                        -     both are end-blown;
                        -     both are solo instruments;
                        -     both belong to the same family;
                        -     both do not need electrical power.

(b)       
(i)   Four Sonatas for the Recorder;
      Six Sonatas for the Recorder;
      Three Sonatas for the Recorder;
      Sonatas for three Recorders;
      Recorder suite in A minor.  

(ii) G.F. Handel;
      Daniel Purcell;
      Telemann;
      Mattheson;
      George Philip.

(c)       
(i) Cracking;
(ii) blockage of the cavity;
(iii) Melting;
(iv) Non-alignment of the parts, when separated.