Question

D. Surnames (Civil Code, arts. 364-380, Family Code, arts. 176, 189, and 193, R.A. No. 9048, R.A. No. 10172)

Question III:

Mr. Juan Reyes and Ms. Maria Santos got married in 2005. Upon marriage, Ms. Santos decided to hyphenate her surname, adopting the surname "Reyes-Santos". They were blessed with a daughter in 2008, whom they named Sofia Reyes-Santos.

In 2014, Mr. Reyes and Ms. Santos decided to legally change their daughter Sofia's surname to "Reyes" only. They availed of the provisions of R.A. No. 9048, amending the entry in Sofia's birth certificate to reflect the change in her surname.

In 2016, Sofia turned 18 years old and decided to change her surname back to "Reyes-Santos". She filed a petition for correction of sex and correcting entries under R.A. No. 10172. In her petition, she stated that she wishes to use both her parents' surnames.

Assuming you are the court clerk handling Sofia's petition, answer the following questions:

1. What are the legal bases for Mr. Reyes and Ms. Santos' decision to change Sofia's surname to "Reyes" only in 2014?
2. Under R.A. No. 9048, can Sofia change her surname back to "Reyes-Santos" without going through a court proceeding? Explain your answer.
3. In Sofia's petition for correction of sex and correcting entries under R.A. No. 10172, what will be the factors that the court will consider in determining whether to grant the change of surname back to "Reyes-Santos"?