The majority of improved varieties of sugarcane are produced by crosses between Noble-cane and Cob-cane, which are respectively:

• A
  $Saccharum \text{ } robustum$ and $S. \text{ } spontaneum$
• B
  $S. \text{ } spontaneum$ and $S. \text{ } officinarum$
• C
  $S. \text{ } officinarum$ and $S. \text{ } robustum$
• D
  $S. \text{ } officinarum$ and $S. \text{ } spontaneum$