question when using options in headers..

I have a question when sending packets which have header options, as i 
didn't find any examples on it.

q1:
Is this order of packet building correct?
e.g. TCP:
1- build_options()
2- build_tcp_header-with payload specified, length = paylod_s+20 (or should 
i add: + option_length)
3-build_build_ipv4(LIBNET_RAW4)
4-write()

can I send a packet with no options and store the tags of the functions and 
then later use those tags to send another one WITH options, or would it be 
considered like a packet with a different protocol? (so I would have to 
clear() the context first it first)

q2:
Whats best in sending packets with different protocols:
a) defining only one libnet context and using it to send pkts of all 
protocols by calling libnet_clear_packet() after each libnte_write() 
operation.
b)defining a libnet context for each type of protocol I use and modifying 
the parameters later when needed with the tag.

q3:
even if i use the _ADV suffix the cull pkt returns an error that it was not 
advanced mode initialized.

Thanks in advance and i REALLY hope this time someone answers me.

Regards

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