What is Z value range for species area relationship among continents?

The correct answer is Option (3) → 0.6 to 1.2

Option (3) 0.6 to 1.2 — Correct. For very large areas such as continents, Z is 0.6 to 1.2.

NCERT Extract:
Patterns of Biodiversity – “… Ecologists have discovered that the value of Z lies in the range of 0.1 to 0.2, regardless of the taxonomic group or the region (whether it is the plants in Britain, birds in California or molluscs in New York state, the slopes of the regression line are amazingly similar). But, if you analyse the species-area relationships among very large areas like the entire continents, you will find that the slope of the line to be much steeper (Z values in the range of 0.6 to 1.2).”