Which of the following on mixing will give rise to maximum heat of reaction ?
a. 100 mL of 0.1 M HCl + 40 mL of 0.1 M NaOH
b. 60 mL of 0.1 M HCl + 60 mL of 0.1 M NaOH
c. 40 mL of 0.1 M HCl + 30 mL of 0.1 M NaOH
d. 40 mL of 0.1 M HCl + 100 mL of 0.1 M NaOH