ok in that case you can look on caches website
www.cache.org.uk look under the level 3 page and you can see the units they will have different names but the same content as c and g which is an awful website. the optional units are not in text books cos theres too many to choose from and you should pick those you know about i would URGE you to report your provider to city and guilds theres too many private people out there delivering appalling courses. it is never too late to change to a different provider