(b) Stock options The Company maintains a Rol

(b) Stock options
The Company maintains a Rolling Stock Option Plan providing for the issuance of stock
options up to 10% of the Company’s issued and outstanding common shares at the time of
the grant. The Company may grant stock options from time to time to its directors,
officers, employees and other service providers. The stock options vest as to 25% on the
date of the grant and 25% on each of the next three anniversaries thereafter for a total
vesting period of 36 months.
The continuity of the number of stock options issued and outstanding is as follows:
Number of Weighted average
stock options exercise price
$
Outstanding, December 31, 2016 12,410,000 0.20
Granted 6,845,000 0.31
Exercised (1,515,000) 0.12
Expired (500,000) 0.40
Cancelled (1,505,000) 0.23
Outstanding, December 31, 2017 15,735,000 0.24
Granted 300,000 0.30
Exercised (872,500) 0.10
Cancelled (425,000) 0.26
Outstanding, March 31, 2018 14,737,500 0.25