One key difference between achievement and aptitude tests is that achievement tests

One key difference between achievement and aptitude tests is that achievement tests
 
  a) assess current attainment, while aptitude tests estimate future performance.
   b) estimate current intellectual level, while aptitude tests assess current mastery of skills.
  Review a sampling of typical instruments
  Analyze whether course preparation can boost scores
   c) focus on a broad array of intellectual abilities, while aptitude tests focus on a narrower, more focused range of abilities.
  Review a sampling of typical instruments
  Analyze whether course preparation can boost scores
   d) focus on a student's potential, while aptitude tests focus on a student's current proficiency.
  Review a sampling of typical instruments
  Analyze whether course preparation can boost scores