Summons under section 131(1A)

Dear Experts, I have received IT department's summons under section 131(1A) for AYs 2016-17 and 2017-18 requiring me to disclose my financial interest in 2 foreign accounts that I held at that time, one was a foreign brokerage account and the other was a foreign pension account (IRA). I am still holding the brokerage account. As I was RNOR in both these years, hence I did not disclose my foreign income/assets in the IT returns that I filed for these years. Also, I was a NRI for 9 prior years, which is when I opened these accounts and all the funds deposited in these accounts was from my income as an NRI (there were no funds transferred from India to these accounts). Now these summons are asking me to :
a) Disclose my investments and also income accrued year wise from these foreign accounts.
b) Provide documents evidencing the date of opening of these accounts.
c) Summon also states, "If you hold as a beneficial owner/beneficiary/settlor or otherwise, any asset (including any bank account or financial interest in any entity) located outside India, or have signing authority in any account located outside India, please list details of such assets or account located outside India along with supporting documents. Please note that financial interest includes shareholding, directorship, beneficial ownership or other forms of pecuniary interest, directly or indirectly."

I have the following questions in this regard:
1. Regarding point (a) above, Do I need to disclose my investments/income from these accounts, given that I was RNOR for these assessment years and NRI prior to that? If no, then what should my response be? If yes, then for which years should I disclose this information, since the summons mention 'year wise'? 
2. Regarding point (b) above, Do I need to provide evidence of date of account opening, even though the accounts were opened when I was a NRI?
3. Regarding point (c) above, do I need to disclose my foreign accounts/assets even though I was RNOR for these assessment years and NRI prior to that? If no, then what should my response be? If yes, then what account details should be disclosed and for which year/s, viz, only for assessment years or held in prior years and/or later years? Also, what documents do I need to submit?

4. These summons are for AYs 2016-17 and 2017-18, viz, for time periods that are 7 years ago and 6 years ago respectively. How far back can these summons be issued? 

Thanks in advance for your help!