In developing abrasive ceramics which are used to wear, grind or cut away other materials which are (necessarily) softer, they should have, besides wear resistance.
1. A High degree of toughness
2. A low degree of toughness
3. Refractoriness
Which of the above is/are correct?
(a) 1 only (b) 2 only
(c) 1 and 3 (d) 2 and 3