Identify the regular verb from the verbs given below.

• We comprehend "Regular and Irregular styles of verbs" as a foundation concept of English grammar. There are about 200 irregular verbs known to date.
  Regular verbs have similar simple tense forms and perfect participle forms or the 3rd styles of their verbs.
  For example- the easy past and perfect participle sort of ‘dance’ are ‘danced’.
• Irregular verbs don't follow a typical pattern showcasing the identical words in past and participial styles of their root verbs.
  For example, Drink is written as drank and drunk within the simple tense (V2) and perfect participle (V3) forms respectively.
• We can see a transparent difference between the 2 forms.
• Now, let’s observe the given options-
  Option A- ‘Bled’ is the simple past of ‘Bleed’ with Bled because the participial form likewise. Although similar, they do not follow the everyday pattern to be called as everyday verbs. Hence, it's an incorrect option.
  Option B- ‘Bear’ has Bore and Borne as its simple past and participle forms respectively, an ideal instance of irregular verbs ruling it out of the list. Hence, it's an incorrect option.
  Option C- ‘Bet’ contains similar simple past and participial forms namely ‘Bet and Bet’. But we conclude them as irregular for they neither end with -d nor -ed or -ied. Hence, it's an incorrect option.
  Option D- ‘Beg’ has begged and begged as its simple past and participial forms. Hence, it's the proper option.

Hence, option D is the correct answer.