( a ) seminal vesicle, vas deferens, glans *****, foreskin, bulbourethral gland
( b ) bulbourethral gland, vas deferens, glans *****, foreskin, urethra
( c ) seminal vesicle, ureter, urethra, foreskin, bulbourethral gland
( d ) bulbourethral gland, ureter, glans *****, urethra (internal), urethra (external)