|Question 21Verbal

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High-entropy alloys (HEAS) have been observed to have greater fracture toughness- greater resistance to crack propagation-than conventional alloys. It has been proposed that fracture toughness increases with the proportion of an HEA consisting of cobalt, but data on HEAs compiled by engineer Xuesong Fan show that this is not the case; for example, [Blank]
Which choice most effectively uses data from the table to complete the text?
cobalt constitutes the same proportion of HEA 7 as it does of HEA 95.
A
cobalt constitutes a higher proportion of HEA 15 than it does of HEA 7.
B
cobalt constitutes a substantial proportion of HEA 15 but does not constitute any of HEA 51.
C
cobalt constitutes a different proportion of HEA 25 than it does of HEA 7.
D